Null Chamber

As Null Chamber enters the battlefield, you and an opponent each choose a card name other than a basic land card name.
Spells with the chosen names can't be cast and lands with the chosen names can't be played.

Distorting Lens

{T}: Target permanent becomes the color of your choice until end of turn.

Hidden Retreat

Put a card from your hand on top of your library: Prevent all damage that would be dealt by target instant or sorcery spell this turn.

Disciple of Caelus Nin

When Disciple of Caelus Nin enters the battlefield, starting with you, each player chooses up to five permanents they control. All permanents other than Disciple of Caelus Nin that weren't chosen this way phase out.
Permanents can't phase in.

Equipoise

At the beginning of your upkeep, for each land target player controls in excess of the number you control, choose a land that player controls, then the chosen permanents phase out. Repeat this process for artifacts and creatures. (While they're phased out, they're treated as though they don't exist. They phase in before that player untaps during their next untap step.)

Circle of Protection: Blue

{1}: The next time a blue source of your choice would deal damage to you this turn, prevent that damage.

Circle of Protection: Black

{1}: The next time a black source of your choice would deal damage to you this turn, prevent that damage.

Authority of the Consuls

Creatures your opponents control enter the battlefield tapped.
Whenever a creature enters the battlefield under an opponent's control, you gain 1 life.

Circle of Protection: Artifacts

{2}: The next time an artifact source of your choice would deal damage to you this turn, prevent that damage.

Rune of Protection: White

{W}: The next time a white source of your choice would deal damage to you this turn, prevent that damage.
Cycling {2} ({2}, Discard this card: Draw a card.)

Hushbringer

Flying, lifelink
Creatures entering the battlefield or dying don't cause abilities to trigger.

Mother of Runes

{T}: Target creature you control gains protection from the color of your choice until end of turn.

Sol Ring

Crackdown

Nonwhite creatures with power 3 or greater don't untap during their controllers' untap steps.

Illusionist's Bracers

Whenever an ability of equipped creature is activated, if it isn't a mana ability, copy that ability. You may choose new targets for the copy.
Equip {3}

Circle of Protection: Red

{1}: The next time a red source of your choice would deal damage to you this turn, prevent that damage.

Eye of Singularity

When Eye of Singularity enters the battlefield, destroy each permanent with the same name as another permanent, except for basic lands. They can't be regenerated.
Whenever a permanent other than a basic land enters the battlefield, destroy all other permanents with that name. They can't be regenerated.

Deep Gnome Terramancer

Flash
Mold Earth — Whenever one or more lands enter the battlefield under an opponent's control without being played, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle. Do this only once each turn.

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Giver of Runes

{T}: Another target creature you control gains protection from colorless or from the color of your choice until end of turn.

Circle of Protection: White

{1}: The next time a white source of your choice would deal damage to you this turn, prevent that damage.

Circle of Protection: Green

{1}: The next time a green source of your choice would deal damage to you this turn, prevent that damage.

Rune-Tail's Essence

Prevent all damage that would be dealt to creatures you control.

Rune-Tail, Kitsune Ascendant

When you have 30 or more life, flip Rune-Tail, Kitsune Ascendant.

Rune-Tail, Kitsune Ascendant // Rune-Tail's Essence

Karoo

Karoo enters the battlefield tapped.
When Karoo enters the battlefield, sacrifice it unless you return an untapped Plains you control to its owner's hand.
{T}: Add {C}{W}.

Ashes of the Abhorrent

Players can't cast spells from graveyards or activate abilities of cards in graveyards.
Whenever a creature dies, you gain 1 life.

Eight-and-a-Half-Tails

{1}{W}: Target permanent you control gains protection from white until end of turn.
{1}: Target spell or permanent becomes white until end of turn.

Defensive Formation

Rather than the attacking player, you assign the combat damage of each creature attacking you. You can divide that creature's combat damage as you choose among any of the creatures blocking it.